Advances in the Diagnosis of Barrett's Esophagus.

Barrett's esophagus (BE), the intestinal metaplasia arising from chronic gastroesophageal reflux disease, is the principal identifiable precursor of esophageal adenocarcinoma (EAC), whose incidence rose from 0.4 to 2.8/100,000 person-years between 1975 and 2017 and whose prognosis, once symptomatic, remains poor. Because outcomes depend on intercepting the metaplasia-dysplasia-carcinoma sequence, diagnostic accuracy is decisive. White-light endoscopy with Seattle-protocol biopsy remains the reference standard, yet it is constrained by the following three interrelated weaknesses: sampling error, as random forceps biopsies interrogate only about 3.5% of the Barrett's mucosa; poor reproducibility of dysplasia grading, with interobserver agreement of only κ 0.24-0.27 for the pivotal distinction of low-grade dysplasia; and a substantial burden of missed disease, with roughly one-quarter of EACs diagnosed within a year of an index endoscopy reported as nondysplastic. This review synthesizes the technologies converging to address these gaps. Advanced imaging, encompassing high-definition endoscopy, narrow-band imaging, acetic acid chromoendoscopy, and the optical-biopsy platforms confocal laser and volumetric laser endomicroscopy, raises dysplasia yield by approximately 34% over standard white-light examination. Image-enhanced endoscopy improves targeted detection while remaining complementary to structured biopsy sampling. Molecular, genetic, and epigenetic biomarkers, notably DNA-content abnormalities, p53 immunohistochemistry, and multi-gene methylation panels, add an objective read on progression risk. Their pairing with non-endoscopic sampling, including Cytosponge-TFF3, capsule endoscopy, exhaled volatile organic compounds, and circulating microRNA liquid biopsy, is reshaping screening at population scale, while artificial intelligence standardizes interpretation and narrows the expert-nonexpert gap. Together these advances point toward a risk-stratified, multimodal paradigm, though prospective validation and cost-effectiveness evidence remain prerequisites for guideline adoption.